Question 1 Name two metals which are usually electroplated on cheaper metals for making jewellery?
Question 2 What properties of chromium make it suitable for electroplating it on car bumpers, bath taps and bicycle handlebar?
Question 3 What properties of tin make it suitable for storing food?
Question 4 Which is the polluting waste generated by electroplating factories?
The metal which is deposited in the form of a thin layer has some desired properties which the metal of the object does not possess.
(1) Chromium metal has a shiny appearance and it does not corrode. Chromium metal is quite expensive and hence it is not economical to make whole object out of chromium. so the object is made of a cheaper metal and only a thin coating of chromium metal is deposited all over its surface by electroplating. After chromium plating it looks as if the whole iron or steel object is made of chromium metal. Chromium plating is done on many objects made of iron metal such as bicycle, handlebars, bicycle bell, wheel rims, bathroom fittings, LPG stoves, motorcycle parts, and many, many other objects.
A thin coating of chromium metal on iron and Steel objects make the Iron and Steel objects look shiny and attractive, as well as protects them from corrosion or rusting.
(2) Tin metal has a shiny appearance, it does not corrode and it is non poisonous. Tin cans used for storing food are made by electroplating tin metal on to iron. Due to tin plating over the surface of iron, the food does not come in contact with iron and is protected from getting spoilt .
(3) Electroplating is used to give objects made of a cheap metal coating of a more expensive metals to make them look more attractive. Less expensive metal are electroplated with more expensive metals like silver and gold to make Jewellery or ornaments. These ornaments have the appearance of silver or gold but they are much less expensive.
(4) Aluminium objects look more attractive electroplated with Nickel.
The conducting solutions or electrolytes used in electroplating contain various types of salts which are poisonous. The conducting solutions are usually acidic in nature .The conducting solution used in electroplating process are polluting waste and hence should be disposed of in a proper way so as to protect the environment.